•An intuitive closed-form solution for the EOQ model with compound interest.•A simple, concise and elegant derivation for the closed form solution.•Improvement of the inventory holding cost that ...accounts for compound interest.•Experimental results that demonstrate superiority of the new closed form solution.•Comparisons with existing NPV based approaches for the basic EOQ model.
The standard Economic Order Quantity (EOQ) model is a cornerstone of inventory management. It is one of the oldest and highly recognized models in business and operations research. In the EOQ model, the inventory holding cost consists of two parts: a financial cost that represents the opportunity cost of capital tied up in the inventory and a warehousing cost. In the classical model, the inventory holding cost is expressed as a percentage of the monetary value of the physical inventory, like an interest rate. The classical model assumes simple interest accrual, which is not realistic because compound interest is used in practice; and it is the rule rather than an exception. In this research, we extend the classical model to account for compound interest and develop an intuitive closed form equation for the optimal order quantity.
Ferritin heavy-chain homolog (FerHCH), an iron-binding protein, plays an important role in the host defense against oxidative stress and pathogen infections. In our previous research, Bombyx mori ...native ferritin had an interaction with B. mori nucleopolyhedrovirus (BmNPV). However, the underlying molecular mechanism of single ferritin homolog responses to BmNPV infection remains unclear. In this study, we found that BmNPV titer and B. mori FerHCH (BmFerHCH) expression were positively correlated with the ferric iron concentration. We performed RNA interference (RNAi) and overexpression experiments to investigate the effects of BmFerHCH on BmNPV proliferation. BmFerHCH knockdown suppressed BmNPV proliferation in vivo and in vitro, whereas BmFerHCH overexpression facilitated BmNPV proliferation. In addition, the oxidative stress level was increased significantly in BmN cells after budded virus infection, while BmFerHCH could neutralize the increased ROS production induced by BmNPV. Of note, we found that ROS was involved in BmNPV-induced apoptosis. Through inhibiting ROS, apoptosis was suppressed by BmFerHCH, whereas BmFerHCH knockdown facilitated apoptosis. Therefore, we hypothesize that BmFerHCH-mediated inhibition of virus-induced apoptosis depends on suppressing ROS accumulation and, thereby, facilitates virus replication. These results suggest that BmFerHCH plays an important role in facilitating BmNPV proliferation and modulating BmFerHCH is potential strategy for studying host–pathogen interactions.
•BmFerHCH facilitated BmNPV proliferation.•BmFerHCH neutralized the increasing ROS induced by BmNPV infection.•ROS is required to trigger BmNPV-induced apoptosis.•BmFerHCH inhibits caspase-dependent apoptosis induced by BmNPV infection.
Macroporous ceramic membrane can be used to recover heat and water vapor from the original flue gas in coal-fired power plants, which is conducive to saving water and improving the economic benefits ...of power generation. However, the overall mass and heat transfer model for the application of membrane modules has not been established at present, and the impact of various parameters on economic benefits has rarely been studied. Therefore, a heat and mass transfer model for 45,600 membrane tubes in a 330 MW coal-fired power plant was established in this paper. Then EBSILON software was applied to simulate the entire thermal system to analyze the economic benefits under different parameters, including cooling water temperatures, cooling water flowrates, turbine heat acceptance operating conditions, and ceramic membrane areas. Finally, its net present value was calculated. The results indicated that the cost recovery time of the transport membrane condenser was 6.85 years when the cooling water temperature is 25 °C and cooling water flowrate is 1000 t/h, and the coal consumption rate was reduced by 0.521 g/(kW·h), which provided theoretical and empirical support for industrial applications.
•A membrane heat and mass transfer model from original flue gas was established.•TMC can recover the heat and water from the flue gas, and more corrosion-resistant.•This system has excellent economic benefits and is able to engineering application.
This investigation aims to present thermo-environmental and thermo-economic parametric studies for a new hybrid tri-generation energy system. In system, a regenerative gas turbine cycle (RGTC) is the ...runner system, while Kalina cycle (KC) and ejector refrigeration cycle (ERC) are considered as companion elements. The parametric study is done through validated computational program developed in EES software. Two new functions of levelized total annual emissions and costs (LTAE and LTAC), with two conventional indices of energetic and exergetic efficiencies (ηen and ηex) are defined for system evaluation. Thermodynamics modeling revealed that almost 75 % of total exergy destruction is related to the RGTC. The outputs of parametric study prove that pressure ratio of compressor and pinch-point temperature of heat exchanger 2 are the most and least effective parameters, respectively. Also, for the bottoming cycles, changes in KC design parameters resulted in creation of peak points in all the evaluation criteria; but changes in the ERC design parameters resulted in uniform (ascending or descending) behavior in the evaluation criteria. The NSGA-II optimization procedure (using MATLAB software) results in ηen,opt = 77.17 %, ηex,opt = 38.94 %, LTAEopt = 9.36 kg/kW.yr, and LTACopt = 106.04 €/kW.yr. The payback period and net present value of the tri-generation system are found as 3.74 yr and 1184525.43 €.
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•Novel power, heat, and cold hybrid system is introduced.•Strong thermo-environmental and thermo-economic analyses are presented.•Optimal conditions are sought through genetic algorithm optimization approach.•Optimal Primary energy ratio and exergy efficiency are 77.17 % and 38.94 %.•Optimal Levelized total annual emissions and costs are 9.36 kg/kW.yr and 106.04 €/kW.yr.
•An innovative approach of BIPV economic analysis is presented.•Societal benefit and environmental benefit are analysed.•NPV and DPP of the BIPV are done.•Economic analyses of a BIPV system in four ...countries is presented.•Replacing conventional façade materials with PV modules makes economic sense.
Recent trends and future objectives in sustainable buildings are to reduce energy consumption, and simultaneously try to supply their energy demand within the building employing an environmentally friendly energy resource which leads to a nearly zero energy building (nZEB). Building integrated photovoltaics (BIPV), which is one of the fastest growing industries worldwide currently, refers to photovoltaic cells that are integrated into the building envelope such as facade or roof to generate clean energy from sunshine and is the most remarkable technology to contribute to nZEB purposes. In this paper, an innovative approach of BIPV economic analysis is presented. The proposed method is to quantify the societal and environmental advantages of a BIPV system as much as possible and import these values to the economic analysis in order to see their effects in a lifecycle cost analysis (LCCA). In order to compare the results with the current LCCA, four case studies from Brazil, Italy, China, and Bahrain were chosen, because they were the most recent BIPV system LCCA, and the suggested method was applied on them. The economic analysis showed that with the societal and environmental benefits of the implemented system, replacing conventional façades and roof building materials with BIPV modules will become economically more feasible. As a result, the presented strategy could not only expectantly guide the end user to decide more conscious about the implementation of BIPV systems but also steer governments or decision-makers to support the technology by rational subsidies and incentives.
Ten-switch three-phase three-level inverter (TP-TLI) is receiving more attention owing to the reduced system cost compared to traditional TP-TLIs. However, it still faces serious neutral-point ...voltage (NPV) balance problems. This article proposes a novel virtual space vector modulation (NVSVM) with optimized neutral-point voltage control (NPVC) capability. A set of virtual vectors are selected to generate zero NP current. By analyzing the vector synthesis principle over the full modulation areas, a new control degree, which is utilized to optimize the NPVC capability and reduce line voltage total harmonic distortion (THD), is introduced. Besides, a dead time compensation method based on volt-second balance is also given to reduce the switching loss. The NVSVM not only improves the NPVC capability without dc offset and obvious ac oscillations in NPV under the full range of modulation index and power factor conditions but also reduces line voltage THD and the switching loss. Theoretical analysis shows that the available NP current for the proposed NVSVM is about 2.75 times greater at most than that for traditional VSVM. Simulation and experimental results are given to validate the effectiveness of the NVSVM and control strategies.
At this time Krebo Jantan Restaurant has plans to conduct business development in the field of food. Krebo Jantan Restaurant has a problem as to whether its business development plan can provide ...feasibility for future growth of the company. The purpose of this study is to determine the possibility of the business plan for the development of food business with the limits of research on the assessment of financial aspects. Primary data collection is done through field observation, interview and questionnaire filling. Objects in interviews and surveys are business owners and residents around the place of business. Secondary data are obtained from literature studies. Data were analyzed by using Payback Period (PBP) method, Present Net Value (NPV) method, and Internal Rate of Return (IRR) Method. The result of the research shows the ability of the company to return all investment cost is for four years eight months. Cash funds collected from year to year if assessed at present with a positive value at the end of year 5 (five) and the ability of the company's business to provide annual average return/dividend amounted to 20.494%. Based on the results of financial analysis shows that all economic feasibility criteria are met so that the development of business feasible to be carried out under standard conditions,
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